1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MLO link handling
4 *
5 * Copyright (C) 2022-2024 Intel Corporation
6 */
7 #include <linux/slab.h>
8 #include <linux/kernel.h>
9 #include <net/mac80211.h>
10 #include "ieee80211_i.h"
11 #include "driver-ops.h"
12 #include "key.h"
13 #include "debugfs_netdev.h"
14
ieee80211_link_setup(struct ieee80211_link_data * link)15 void ieee80211_link_setup(struct ieee80211_link_data *link)
16 {
17 if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
18 ieee80211_mgd_setup_link(link);
19 }
20
ieee80211_link_init(struct ieee80211_sub_if_data * sdata,int link_id,struct ieee80211_link_data * link,struct ieee80211_bss_conf * link_conf)21 void ieee80211_link_init(struct ieee80211_sub_if_data *sdata,
22 int link_id,
23 struct ieee80211_link_data *link,
24 struct ieee80211_bss_conf *link_conf)
25 {
26 bool deflink = link_id < 0;
27
28 if (link_id < 0)
29 link_id = 0;
30
31 rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf);
32 rcu_assign_pointer(sdata->link[link_id], link);
33
34 link->sdata = sdata;
35 link->link_id = link_id;
36 link->conf = link_conf;
37 link_conf->link_id = link_id;
38 link_conf->vif = &sdata->vif;
39
40 wiphy_work_init(&link->csa.finalize_work,
41 ieee80211_csa_finalize_work);
42 wiphy_work_init(&link->color_change_finalize_work,
43 ieee80211_color_change_finalize_work);
44 wiphy_delayed_work_init(&link->color_collision_detect_work,
45 ieee80211_color_collision_detection_work);
46 INIT_LIST_HEAD(&link->assigned_chanctx_list);
47 INIT_LIST_HEAD(&link->reserved_chanctx_list);
48 wiphy_delayed_work_init(&link->dfs_cac_timer_work,
49 ieee80211_dfs_cac_timer_work);
50
51 if (!deflink) {
52 switch (sdata->vif.type) {
53 case NL80211_IFTYPE_AP:
54 ether_addr_copy(link_conf->addr,
55 sdata->wdev.links[link_id].addr);
56 link_conf->bssid = link_conf->addr;
57 WARN_ON(!(sdata->wdev.valid_links & BIT(link_id)));
58 break;
59 case NL80211_IFTYPE_STATION:
60 /* station sets the bssid in ieee80211_mgd_setup_link */
61 break;
62 default:
63 WARN_ON(1);
64 }
65
66 ieee80211_link_debugfs_add(link);
67 }
68 }
69
ieee80211_link_stop(struct ieee80211_link_data * link)70 void ieee80211_link_stop(struct ieee80211_link_data *link)
71 {
72 if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
73 ieee80211_mgd_stop_link(link);
74
75 wiphy_delayed_work_cancel(link->sdata->local->hw.wiphy,
76 &link->color_collision_detect_work);
77 wiphy_work_cancel(link->sdata->local->hw.wiphy,
78 &link->color_change_finalize_work);
79 wiphy_work_cancel(link->sdata->local->hw.wiphy,
80 &link->csa.finalize_work);
81
82 if (link->sdata->wdev.links[link->link_id].cac_started) {
83 wiphy_delayed_work_cancel(link->sdata->local->hw.wiphy,
84 &link->dfs_cac_timer_work);
85 cfg80211_cac_event(link->sdata->dev,
86 &link->conf->chanreq.oper,
87 NL80211_RADAR_CAC_ABORTED,
88 GFP_KERNEL, link->link_id);
89 }
90
91 ieee80211_link_release_channel(link);
92 }
93
94 struct link_container {
95 struct ieee80211_link_data data;
96 struct ieee80211_bss_conf conf;
97 };
98
ieee80211_tear_down_links(struct ieee80211_sub_if_data * sdata,struct link_container ** links,u16 mask)99 static void ieee80211_tear_down_links(struct ieee80211_sub_if_data *sdata,
100 struct link_container **links, u16 mask)
101 {
102 struct ieee80211_link_data *link;
103 LIST_HEAD(keys);
104 unsigned int link_id;
105
106 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
107 if (!(mask & BIT(link_id)))
108 continue;
109 link = &links[link_id]->data;
110 if (link_id == 0 && !link)
111 link = &sdata->deflink;
112 if (WARN_ON(!link))
113 continue;
114 ieee80211_remove_link_keys(link, &keys);
115 ieee80211_link_debugfs_remove(link);
116 ieee80211_link_stop(link);
117 }
118
119 synchronize_rcu();
120
121 ieee80211_free_key_list(sdata->local, &keys);
122 }
123
ieee80211_free_links(struct ieee80211_sub_if_data * sdata,struct link_container ** links)124 static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
125 struct link_container **links)
126 {
127 unsigned int link_id;
128
129 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++)
130 kfree(links[link_id]);
131 }
132
ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data * sdata)133 static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
134 {
135 unsigned int i, j;
136
137 for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
138 struct ieee80211_link_data *link1;
139
140 link1 = sdata_dereference(sdata->link[i], sdata);
141 if (!link1)
142 continue;
143 for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
144 struct ieee80211_link_data *link2;
145
146 link2 = sdata_dereference(sdata->link[j], sdata);
147 if (!link2)
148 continue;
149
150 if (ether_addr_equal(link1->conf->addr,
151 link2->conf->addr))
152 return -EALREADY;
153 }
154 }
155
156 return 0;
157 }
158
ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data * sdata,u16 valid_links,u16 dormant_links)159 static void ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data *sdata,
160 u16 valid_links, u16 dormant_links)
161 {
162 sdata->vif.valid_links = valid_links;
163 sdata->vif.dormant_links = dormant_links;
164
165 if (!valid_links ||
166 WARN((~valid_links & dormant_links) ||
167 !(valid_links & ~dormant_links),
168 "Invalid links: valid=0x%x, dormant=0x%x",
169 valid_links, dormant_links)) {
170 sdata->vif.active_links = 0;
171 sdata->vif.dormant_links = 0;
172 return;
173 }
174
175 switch (sdata->vif.type) {
176 case NL80211_IFTYPE_AP:
177 /* in an AP all links are always active */
178 sdata->vif.active_links = valid_links;
179
180 /* AP links are not expected to be disabled */
181 WARN_ON(dormant_links);
182 break;
183 case NL80211_IFTYPE_STATION:
184 if (sdata->vif.active_links)
185 break;
186 sdata->vif.active_links = valid_links & ~dormant_links;
187 WARN_ON(hweight16(sdata->vif.active_links) > 1);
188 break;
189 default:
190 WARN_ON(1);
191 }
192 }
193
ieee80211_vif_update_links(struct ieee80211_sub_if_data * sdata,struct link_container ** to_free,u16 new_links,u16 dormant_links)194 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
195 struct link_container **to_free,
196 u16 new_links, u16 dormant_links)
197 {
198 u16 old_links = sdata->vif.valid_links;
199 u16 old_active = sdata->vif.active_links;
200 unsigned long add = new_links & ~old_links;
201 unsigned long rem = old_links & ~new_links;
202 unsigned int link_id;
203 int ret;
204 struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link;
205 struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
206 struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
207 bool use_deflink = old_links == 0; /* set for error case */
208
209 lockdep_assert_wiphy(sdata->local->hw.wiphy);
210
211 memset(to_free, 0, sizeof(links));
212
213 if (old_links == new_links && dormant_links == sdata->vif.dormant_links)
214 return 0;
215
216 /* if there were no old links, need to clear the pointers to deflink */
217 if (!old_links)
218 rem |= BIT(0);
219
220 /* allocate new link structures first */
221 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
222 link = kzalloc(sizeof(*link), GFP_KERNEL);
223 if (!link) {
224 ret = -ENOMEM;
225 goto free;
226 }
227 links[link_id] = link;
228 }
229
230 /* keep track of the old pointers for the driver */
231 BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
232 memcpy(old, sdata->vif.link_conf, sizeof(old));
233 /* and for us in error cases */
234 BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
235 memcpy(old_data, sdata->link, sizeof(old_data));
236
237 /* grab old links to free later */
238 for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
239 if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
240 /*
241 * we must have allocated the data through this path so
242 * we know we can free both at the same time
243 */
244 to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
245 typeof(*links[link_id]),
246 data);
247 }
248
249 RCU_INIT_POINTER(sdata->link[link_id], NULL);
250 RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
251 }
252
253 if (!old_links)
254 ieee80211_debugfs_recreate_netdev(sdata, true);
255
256 /* link them into data structures */
257 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
258 WARN_ON(!use_deflink &&
259 rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);
260
261 link = links[link_id];
262 ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
263 ieee80211_link_setup(&link->data);
264 }
265
266 if (new_links == 0)
267 ieee80211_link_init(sdata, -1, &sdata->deflink,
268 &sdata->vif.bss_conf);
269
270 ret = ieee80211_check_dup_link_addrs(sdata);
271 if (!ret) {
272 /* for keys we will not be able to undo this */
273 ieee80211_tear_down_links(sdata, to_free, rem);
274
275 ieee80211_set_vif_links_bitmaps(sdata, new_links, dormant_links);
276
277 /* tell the driver */
278 ret = drv_change_vif_links(sdata->local, sdata,
279 old_links & old_active,
280 new_links & sdata->vif.active_links,
281 old);
282 if (!new_links)
283 ieee80211_debugfs_recreate_netdev(sdata, false);
284 }
285
286 if (ret) {
287 /* restore config */
288 memcpy(sdata->link, old_data, sizeof(old_data));
289 memcpy(sdata->vif.link_conf, old, sizeof(old));
290 ieee80211_set_vif_links_bitmaps(sdata, old_links, dormant_links);
291 /* and free (only) the newly allocated links */
292 memset(to_free, 0, sizeof(links));
293 goto free;
294 }
295
296 /* use deflink/bss_conf again if and only if there are no more links */
297 use_deflink = new_links == 0;
298
299 goto deinit;
300 free:
301 /* if we failed during allocation, only free all */
302 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
303 kfree(links[link_id]);
304 links[link_id] = NULL;
305 }
306 deinit:
307 if (use_deflink)
308 ieee80211_link_init(sdata, -1, &sdata->deflink,
309 &sdata->vif.bss_conf);
310 return ret;
311 }
312
ieee80211_vif_set_links(struct ieee80211_sub_if_data * sdata,u16 new_links,u16 dormant_links)313 int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
314 u16 new_links, u16 dormant_links)
315 {
316 struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
317 int ret;
318
319 ret = ieee80211_vif_update_links(sdata, links, new_links,
320 dormant_links);
321 ieee80211_free_links(sdata, links);
322
323 return ret;
324 }
325
_ieee80211_set_active_links(struct ieee80211_sub_if_data * sdata,u16 active_links)326 static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata,
327 u16 active_links)
328 {
329 struct ieee80211_bss_conf *link_confs[IEEE80211_MLD_MAX_NUM_LINKS];
330 struct ieee80211_local *local = sdata->local;
331 u16 old_active = sdata->vif.active_links;
332 unsigned long rem = old_active & ~active_links;
333 unsigned long add = active_links & ~old_active;
334 struct sta_info *sta;
335 unsigned int link_id;
336 int ret, i;
337
338 if (!ieee80211_sdata_running(sdata))
339 return -ENETDOWN;
340
341 if (sdata->vif.type != NL80211_IFTYPE_STATION)
342 return -EINVAL;
343
344 if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
345 return -EINVAL;
346
347 /* nothing to do */
348 if (old_active == active_links)
349 return 0;
350
351 for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++)
352 link_confs[i] = sdata_dereference(sdata->vif.link_conf[i],
353 sdata);
354
355 if (add) {
356 sdata->vif.active_links |= active_links;
357 ret = drv_change_vif_links(local, sdata,
358 old_active,
359 sdata->vif.active_links,
360 link_confs);
361 if (ret) {
362 sdata->vif.active_links = old_active;
363 return ret;
364 }
365 }
366
367 for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
368 struct ieee80211_link_data *link;
369
370 link = sdata_dereference(sdata->link[link_id], sdata);
371
372 ieee80211_teardown_tdls_peers(link);
373
374 __ieee80211_link_release_channel(link, true);
375
376 /*
377 * If CSA is (still) active while the link is deactivated,
378 * just schedule the channel switch work for the time we
379 * had previously calculated, and we'll take the process
380 * from there.
381 */
382 if (link->conf->csa_active)
383 wiphy_delayed_work_queue(local->hw.wiphy,
384 &link->u.mgd.csa.switch_work,
385 link->u.mgd.csa.time -
386 jiffies);
387 }
388
389 list_for_each_entry(sta, &local->sta_list, list) {
390 if (sdata != sta->sdata)
391 continue;
392
393 /* this is very temporary, but do it anyway */
394 __ieee80211_sta_recalc_aggregates(sta,
395 old_active | active_links);
396
397 ret = drv_change_sta_links(local, sdata, &sta->sta,
398 old_active,
399 old_active | active_links);
400 WARN_ON_ONCE(ret);
401 }
402
403 ret = ieee80211_key_switch_links(sdata, rem, add);
404 WARN_ON_ONCE(ret);
405
406 list_for_each_entry(sta, &local->sta_list, list) {
407 if (sdata != sta->sdata)
408 continue;
409
410 __ieee80211_sta_recalc_aggregates(sta, active_links);
411
412 ret = drv_change_sta_links(local, sdata, &sta->sta,
413 old_active | active_links,
414 active_links);
415 WARN_ON_ONCE(ret);
416
417 /*
418 * Do it again, just in case - the driver might very
419 * well have called ieee80211_sta_recalc_aggregates()
420 * from there when filling in the new links, which
421 * would set it wrong since the vif's active links are
422 * not switched yet...
423 */
424 __ieee80211_sta_recalc_aggregates(sta, active_links);
425 }
426
427 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
428 struct ieee80211_link_data *link;
429
430 link = sdata_dereference(sdata->link[link_id], sdata);
431
432 /*
433 * This call really should not fail. Unfortunately, it appears
434 * that this may happen occasionally with some drivers. Should
435 * it happen, we are stuck in a bad place as going backwards is
436 * not really feasible.
437 *
438 * So lets just tell link_use_channel that it must not fail to
439 * assign the channel context (from mac80211's perspective) and
440 * assume the driver is going to trigger a recovery flow if it
441 * had a failure.
442 * That really is not great nor guaranteed to work. But at least
443 * the internal mac80211 state remains consistent and there is
444 * a chance that we can recover.
445 */
446 ret = _ieee80211_link_use_channel(link,
447 &link->conf->chanreq,
448 IEEE80211_CHANCTX_SHARED,
449 true);
450 WARN_ON_ONCE(ret);
451
452 ieee80211_mgd_set_link_qos_params(link);
453 ieee80211_link_info_change_notify(sdata, link,
454 BSS_CHANGED_ERP_CTS_PROT |
455 BSS_CHANGED_ERP_PREAMBLE |
456 BSS_CHANGED_ERP_SLOT |
457 BSS_CHANGED_HT |
458 BSS_CHANGED_BASIC_RATES |
459 BSS_CHANGED_BSSID |
460 BSS_CHANGED_CQM |
461 BSS_CHANGED_QOS |
462 BSS_CHANGED_TXPOWER |
463 BSS_CHANGED_BANDWIDTH |
464 BSS_CHANGED_TWT |
465 BSS_CHANGED_HE_OBSS_PD |
466 BSS_CHANGED_HE_BSS_COLOR);
467 }
468
469 old_active = sdata->vif.active_links;
470 sdata->vif.active_links = active_links;
471
472 if (rem) {
473 ret = drv_change_vif_links(local, sdata, old_active,
474 active_links, link_confs);
475 WARN_ON_ONCE(ret);
476 }
477
478 return 0;
479 }
480
ieee80211_set_active_links(struct ieee80211_vif * vif,u16 active_links)481 int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
482 {
483 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
484 struct ieee80211_local *local = sdata->local;
485 u16 old_active;
486 int ret;
487
488 lockdep_assert_wiphy(local->hw.wiphy);
489
490 if (WARN_ON(!active_links))
491 return -EINVAL;
492
493 old_active = sdata->vif.active_links;
494 if (old_active == active_links)
495 return 0;
496
497 if (!drv_can_activate_links(local, sdata, active_links))
498 return -EINVAL;
499
500 if (old_active & active_links) {
501 /*
502 * if there's at least one link that stays active across
503 * the change then switch to it (to those) first, and
504 * then enable the additional links
505 */
506 ret = _ieee80211_set_active_links(sdata,
507 old_active & active_links);
508 if (!ret)
509 ret = _ieee80211_set_active_links(sdata, active_links);
510 } else {
511 /* otherwise switch directly */
512 ret = _ieee80211_set_active_links(sdata, active_links);
513 }
514
515 return ret;
516 }
517 EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
518
ieee80211_set_active_links_async(struct ieee80211_vif * vif,u16 active_links)519 void ieee80211_set_active_links_async(struct ieee80211_vif *vif,
520 u16 active_links)
521 {
522 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
523
524 if (WARN_ON(!active_links))
525 return;
526
527 if (!ieee80211_sdata_running(sdata))
528 return;
529
530 if (sdata->vif.type != NL80211_IFTYPE_STATION)
531 return;
532
533 if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
534 return;
535
536 /* nothing to do */
537 if (sdata->vif.active_links == active_links)
538 return;
539
540 sdata->desired_active_links = active_links;
541 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->activate_links_work);
542 }
543 EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);
544